The Palatka daily news. (Palatka, Fla.) 1884-1888, 1887-06-17
Healthy Trees VS.. Pest Insects.

Pacific Fruit Grower.
1t appears to be the firm belief of
many fruit-growers that insect pests can
thrive only ON sick or unhealthy trees,
and that there is something repulsive in
a perfectly healthy tree that has a tend
ency to enable the tree to rid itself of in
sect pests. especially those commonly
known as scale insects, or more vulgarly
scale baqs This. however is in direct
opposition to known facts; namely, that
the more healthy the tree, the more Wig
orous will be the scale insets that infest
it. This is especially the case with the
cottony cushion scale, but is equally
true of all other kinds of scale insects
with which am acquainted
One of the chief causes that has given
to this belief is the fact that the sickly,
half-dead trees are found To be thickly
infested with the scale insects, while the
healthy vigorous trees are compare
lively free from them; but the fact in
nearly every case is that the insects have
been quietly at work upon the slckly
trees for a longer or shorter time unOD
served, and that their presence was first
detected only after they had robbed the
trees of much of their vitality,-the
sickIy aspect of the trees (the direct re-
suit of the work of the insects) causing
the grower to carefully examine them to
ascertain if possible, the cause of their
lessened vitality, and finding them in
tested with scale insects he naturally
turns to the other trees, which have not
been so long infested, and are therefore
in a more vigorous condition, and hnt-
ing fewer scale insects upon them he
concludes that the insects flourish best
on sicklv trees-a conclusion he never
would have reached had he been aware
of the length of time his sickly trees had
been infested.
Another erroneous Ideals that a perfect
ly healthy tree has the power OF Kidding
itself of the scale insects that Infest II.
Some kinds of insects flourish best upon
dead or dying trees, but the scale insects
do not belong To this category; the pure,
healthy sap of the tree Is best suited to
their wants. their health and vigor keep
ing apace with the health and vigor of
the tree they infest. Trees growing in
rich soil will of course, be better able
to withstand the attacks of scale insects,
since they can more easily secure the
necessary elements from the soil
to replace those taken from them
by the insects; but when once
certain number of scale insects become
aft xed to a tree, no amount of fertIlIZ-
ing will enable the tree to rid itself of a
single scale insect.
That fruit trees do sometimes become
quite free from the scale insects that
once infested them, independent of any
thing we may do for them, Is true i'll a
few cases, especially in regard to the
black scale; but we must seek for "a so
luton of this phenomenon either in the
undue increase of its parasites.
or i'm SOME unfavOrable eli
matte conditions. Instances have
come under my own observation where
large numbers of the young of the black
scale had been killed by excessively hot
weather, but this condition of the
weather seems to have had no in furious
effect upon either the red or the cOttony
cushion scale. In fact. this latter pest Is
most active, and multiplies the most
rapidly during the hottest part of the
summer season.
One of our exchanges contains the
statement that many of the orange trees
that have been nearly killed by the at
tacks of the red scales were, at least in
one locality, apparently fast get
ting rid of these pests and starting into
a new growth. This Is precisely what
would naturally be expected. When
the insects have so reduced the vitality
of the tree that it no longer supplies
them with "A sufficient quantity of sap
for their sustenance, they must neces-
sarily perish from starvation, while the
tree thus freed from the hosts of insects
that were constantly drawing out its
life blood. would slowly gather sufficient
strength to make a feeble attempt at a
new growth. This is one of the methods
that nature employs to prevent the
complete determination of any kind of
tree or plant by the insects that feed up
on it. Do we not learn from this that by
fertiliZing an infested tree we at the
| same time feed the scale insects which
| infest it, and in case the fertiliZing ele-
rrc.I in S11ffiaIaslt tn
to supply thesese insects with all the
food they require, we enable the tree to
perform its proper functions indepen-
dent of the insects that infest it: